Sore throat followed by head congestion and fever - need diagnosis?

If a diagnosis is what you want, you can't get that online, sight unseen or by some one other than an NP, PA, DO or MD.

Treat it as a minor viral infection. There is a thing called an incubation period. This is the interval of time that passes after an initial infection and the first day symptoms appear. It's impossible that you could have picked up something from the campus infirmary and then come down with a sore throat the same day. Whatever it is you have, you already had it when you went to the infirmary.